1. Field of the Invention
The present invention relates to a driving support apparatus for a vehicle configured, when a subject vehicle is to turn in road, to set a space for the subject vehicle to cut into in a lane to which the subject vehicle attempts to enter, obtain an entry start time for allowing the subject vehicle to enter the space to cut into, and, when the entry start time is reached, output an entry start instruction signal to an instruction display unit to notify the driver of the timing of starting steering for turning.
2. Description of Related Art
For turning while traveling on an expressway, such as entering a driving lane from a merge lane, changing from a driving lane to a passing lane, or changing back from a passing lane to a driving lane, the driver grasps road traveling conditions of the lane to which the vehicle is to change based on information that can be obtained through side mirrors (door mirrors and fender mirrors) and a rearview mirror while looking ahead carefully, and sets a vehicle speed and a timing (steering start timing) for starting turning to smoothly turn and cut into the lane. However, the driver has to be skilled to some extent so as to perform the series of operations while looking ahead carefully. This is difficult for beginner drivers and makes them avoid driving on an expressway.
Therefore, there have been proposed various driving support apparatuses allowing a beginner driver to easily turn on an expressway. For example, Japanese Patent Application Laid-Open (JP-A) No. 2008-222153 discloses a technique of, when a subject vehicle is to enter a driving lane from a merge lane, detecting conditions of other vehicles within an area corresponding to the driving lane, such as distance from the subject vehicle, vehicle length, vehicle speed, acceleration, by means of a rearview camera mounted on a door mirror to calculate an empty space, determining the empty space as a merge position if the empty space is determined to have a sufficient length for the subject vehicle to cut into and to be reachable without excessive acceleration, and displaying the merge position in the door mirror so as to allow the driver to correctly grasp the timing for the subject vehicle to cut thereinto.
In the technique disclosed in JP-A No. 2008-222153, however, a device for displaying an image showing the merge position in the door mirror is required, which requires the door mirror to have a special structure. The technique thus lacks versatility, and increases product cost.
In situations such as changing to a next lane, changing from a driving lane to a passing lane or changing back to a driving lane from a passing lane in addition to the situation of making the subject vehicle enter a driving lane from a merge lane while driving on an expressway, it is difficult for a beginner driver to determine the timing therefor. It would be often useful to offer a driving support in such situations in many cases.
In the technique disclosed in JP-A No. 2008-222153, however, a target area for merging support is determined by a car navigation system through map matching between position information from a GPS and map data, and conditions of a driving lane are detected automatically if an area is determined to be a target area for merging support. Therefore, the technique lacks convenience since it cannot be applied to a vehicle on which a GPS is not mounted, and cannot be used in situations other than making a subject vehicle enter a driving lane from a merge lane.